Examining Racial Disparities in Treatment and Outcomes of Waldenström Macroglobulinemia Patients

In a study conducted presented at the 2021 American Society of Hematology Annual Meeting, researchers led by Aisha S. Patel, MBBS, MRCP, aimed to discern baseline demographics, symptoms, and survival outcomes of Waldenström macroglobulinaemia (WM) among different ethnic groups in the U.K.

“This first report on ethnic disparities in WM and non-IgM LPL in the U.K. identified key differences in presentation of disease. Ethnic minorities present at a younger age, with a lower paraprotein,” the researchers concluded. They added that further analysis exploring associations with socioeconomic status, deprivation indices, and comorbidities “are ongoing.”

As the researchers explained, approximately 400 patients are diagnosed with WM in the U.K. However, unlike in the U.S., WM outcomes between different ethnic groups are not well elucidated.

In this retrospective study, researchers reviewed data from the WMUK Rory Morrison Registry, which collates data on WM and non-IgM lymphoplasmacytic lymphoma (LPL) from 20 U.K. centers, diagnosed between June 1978 and May 2021. The analysis consisted of 732 patients with recorded ethnicity. The cohort was 90% White, and all others were collectively termed “Ethnic Minorities” (9%). Of this group, 56% were Asian, 27% were mixed-race, and 17% were Black.

The results showed that ethnic minorities presented with WM at a younger age compared to their White counterparts (60 vs. 64 years; p = 0.01) and had a significantly lower paraprotein at diagnosis (11 vs. 18 g/L; p = 0.05). MYD88 L265P mutation, which was tested in 34% of patients, was found to be positive in most White patients (87%), and notably less common in ethnic minority patients (p = 0.09), most significantly in the Asian cohort compared to White, the researchers noted. Moreover, the study found that the ethnic minorities cohort had a smaller proportion of WM diagnoses compared to White cohort (77% vs. 93%; p = 0.02), with the Asian cohort accounting for the highest proportion of non-IgM LPL (15% vs. 4%; p = 0.002).

In terms of survival, for ethnic minorities, at a median follow-up of seven years, 17 patients died (6% were considered disease-related), and the median overall survival was not reached. The investigators noted that the estimated five-year and 10- year rates of overall survival were 91% and 75%, respectively.